The present disclosure relates to solid-state imaging devices and methods of manufacturing the devices.
Reducing dark currents and afterimages in solid-state imaging devices is studied. In order to reduce dark currents and afterimages, providing a pinning layer is suggested. For example, Japanese Unexamined Patent Publication No. 2012-60076 teaches providing a pinning layer of the conductivity type opposite to a charge region (i.e., a floating diffusion (FD)) to reduce contact of a depletion layer generated at the boundary of the pn junction of the FD with the surface of a semiconductor substrate, thereby reducing charge recombination. This structure is expected to reduce dark currents and afterimages caused by a trap level, etc.